---
schema_version: "secwatch.filing_event.v1"
accession: "0001628280-26-026259"
form_type: "8-K"
ticker: "FHTX"
cik: "0001822462"
company_name: "Foghorn Therapeutics Inc."
filed_at: "2026-04-21T23:59:59+00:00"
generated_at: "2026-05-15T05:09:12.185201+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# Foghorn presents preclinical data at AACR: FHD-909 combo shows complete regression and immune memory

## Summary
- FHD-909 (SMARCA2 inhibitor) plus anti-PD-1 achieved complete tumor regression and immune memory in preclinical SMARCA4-mutant models.
- Selective CBP degrader FHT-171 showed strong anti-tumor activity and favorable tolerability in heavily pretreated ER+ breast cancer PDX models.
- Selective EP300 degrader outperformed clinical benchmark inobrodib in multiple myeloma models, including pomalidomide-resistant xenografts.
- Cereblon-based selective ARID1B degraders achieved robust degradation with potential for oral bioavailability.

## SEC filing metadata
- accession: 0001628280-26-026259
- form_type: 8-K
- ticker: FHTX
- cik: 0001822462
- company_name: Foghorn Therapeutics Inc.
- filed_at: 2026-04-21T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1822462/000162828026026259/0001628280-26-026259-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1822462/000162828026026259/fhtx-20260421.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001628280-26-026259
- JSON: https://secwatch.observer/filing/0001628280-26-026259.json
- Plain text: https://secwatch.observer/filing/0001628280-26-026259.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.